In order to enhance design quality of vehicles and/or protect the outer surfaces of the vehicles, various exterior members are provided on parts of the upper surfaces of vehicle bodies. For similar purposes, exterior members are sometimes provided on the outer surfaces of vehicle doors as well. Techniques for providing an exterior member on the outer surface of a vehicle door are disclosed in Patent Literature 1 and Patent Literature 2. According to each of Patent Literature 1 and Patent Literature 2, the vehicle door on which the exterior member is provided is a side door for opening and closing a get-in/out opening (door opening) formed in the vehicle body. A lower section of the outer surface of the side door is covered with the exterior member formed of resin.
Such conventionally-known vehicle door assemblies have the following three room for improvement.
The first room for improvement is as follows. The get-in/out opening (door opening) is formed in the vehicle body in a given size in accordance with design of the vehicle. Further, it is preferable that the get-in/out have a large size to allow a passenger to get in and out to and from the vehicle. In many cases, the side door is manufactured in a different plant from the vehicle body by use of existing manufacturing facilities. In order to manufacture a large-size side door, limitations of capacities of the manufacturing equipment, for example, are often encountered. In a case where the vehicle is designed so that a large get-in/out opening is closed with a relatively small side door, arrangements have to be made such that no gap is formed in a surface direction of the door between a frame section defining the get-in/out opening and the lower end of the side door. In order to avoid, such a gas, it may be conceivable to expand downward an inner panel of the door panel. However, because the door increases in weight in such a case, there is room for improvement with a view to reducing the weight of the vehicle.
Further, in the vehicle door disclosed in Patent Literature 2, a seal member seals between a frame section defining the get-in/out opening and an edge of the side door. When the door is closed (in a closed position), the seal member is sandwiched between the frame section and the edge of the side door. Thus, reactive force acts on the edge of the side door due to the sandwiching of the seal member. If a gap exists in the surface direction of the door, no seal member can be provided on the edge of the side door.
The second room for improvement is as follows. The exterior member disclosed in Patent Literature 2 includes: a panel-shaped exterior member body covering a lower section of the outer surface of the side door; a flange section extending from the lower end of the exterior member body toward the lower edge of the side door; a panel-shaped reduced-thickness section formed integrally with the distal end of the flange section; and an inner wall formed integrally with the exterior member body via the small-thickness section. The reduced-thickness section is a section bendable in the thickness direction and generally called a reduced-thickness hinge. The inner wall is bent inward about the reduced-thickness hinge toward the reverse side of the exterior member body and joined to the reverse surface. Thus, on the lower end of the exterior member body, a closed section part having a closed sectional shape is formed with the exterior member body, the flange section and the inner wall.
Generally, the resin-made exterior member is formed by a resin-molding mold that has a gate (feed opening) formed therein for feeding molten resin into a cavity. Thus, there would be left an unwanted mark of the gate on the molded exterior member; such a mark is positioned on the reverse surface of the flange section so that it is invisible from outside the exterior member. Further, the above-mentioned inner wall is located, across the reduced-thickness hinge from the exterior member body and the flange section. Because a narrowed space is defined between the flange section and the inner wall, a flow, between the flange section and the inner wall, of the molten resin fed through the gate tends to be limited. Thus, in order to smooth the flow of the molten resin, it is preferable to provide the gate in a portion of the cavity having a relatively large space, e.g. a cavity portion corresponding to the flange section.
The vehicle doors are formed in various shapes in accordance with design of the vehicles, and a variety of shapes are required of the exterior members depending on the shapes of the vehicle doors. In some cases, the exterior member may be curved to be slightly concave or recessed inward in the vehicle width direction, while the reduced-thickness hinge is formed straight in such a manner as to be bendable. Therefore, a width of the flange section, i.e. a distance from the reduced-thickness hinge to the lower end of the exterior member body would greatly differ depending on the curved shape of the exterior member.
In the case where the exterior member is curved to be slightly concave or recessed inward in the vehicle width direction as above, the flange section has a minimum width at its middle portion in the longitudinal direction of the door (i.e., front-rear direction of the vehicle body). Thus, the gate sometimes may not be able to be provided on the flange-section-corresponding cavity portion of the cavity in the resin-molding mold. In such a case, there is no other choice but to provide the gate in a cavity portion corresponding to the exterior member body located greatly remote from the reduced-thickness hinge. Namely, there is room for improvement in order to allow the molten resin to flow uniformly throughout the entire range of the cavity. Therefore, limitations would be encountered in increasing a strength of the exterior member.
The third room for improvement is as follows. Generally, the bodies of the vehicle side doors have a drainage hole for discharging water having entered the interior of the door body, as known from Patent Literature 2 and Patent Literature 3.
In the vehicle side door disclosed in Patent Literature 2, the drainage hole and the seal member are provided in and on the lower end of the door body, respectively, and the lower section of the outer surface of the side door is covered with the exterior member. The exterior member is formed in a gutter shape such that it includes a portion positionally corresponding to the drainage hole and it covers the lower end of the lower end of the door body. More specifically, the drainage hole is formed in the bottom of the exterior member, and the seal member is a weather strip that contacts and seals the frame section of the get-in/out opening when the side door is closed and that is located closer to the interior of the vehicle than the exterior member.
Further, the vehicle side door disclosed in Patent Literature 3 includes the drainage hole, a weather strip and a seal member provided in and on the lower end of the door body. The weather strip is a member that is located closer to the interior of the vehicle than the exterior member and that contacts and seals a frame section of the get-in/out opening when the side door is closed. The seal member (parting seal), which is formed in a tubular shape and located immediately beneath the drainage hole, has a communication hole capable of introducing thereinto water discharged via the drainage hole.
However, the techniques disclosed in Patent Literature 2 and Patent Literature 3 are disadvantageous in that, if the vehicle is designed so that a large get-in/out opening is closed with a relatively small side door, a gap would be formed between the frame section defining the get-in/out opening and the lower end of the side door. Due to such a gap, no seal member can be provided on the lower edge of the side door. Besides, the drainage hole formed in the lower end of the side door would be located away from the frame section. Thus, arrangements have to be made to prevent water, discharged via the drainage hole, from entering the interior the door through the gap.
If the seal member employed in any one of the vehicle doors disclosed in Patent Literature 1 and Patent Literature 2 is mounted as-is below the drainage hole and in such a manner as to cover the drainage hole, a distance from the drainage hole to the seal member would increase. Thus, the frame section would get wet with water discharged via the drainage hole. Particularly, in cold weather regions, the water having wetted the frame section tends to easily freeze, so that the seal member may adhere to (freeze to) the frame section. Therefore, arrangements have to be made to secure enough durability of the seal member.